Mold cavity locking apparatus

ABSTRACT

A first mold member is supported by a platen for movement between open and closed positions relative to a mating second mold member mounted on the frame which supports the platen. A first wedge member extends across the back of the platen, and a second wedge member is supported by the frame for aligned sliding engagement with the first wedge member to effect locking of the mold members after they are closed. In one embodiment, the second wedge member is also supported for lateral movement to an offset position relative to the first wedge member to provide for quickly opening and closing the mold members. Movement of the first mold member and the movement of the second wedge member are produced by a set of fluid cylinders which are actuated in timed sequence and are effective to exert a continuous force to hold the mold members in their closed positions. In another embodiment, the second wedge member is supported by a plate which may be quickly retracted and extended for opening and closing the mold member.

[ 1 July 3,1973

[ MOLD CAVITY LOCKING APPARATUS [76] Inventor: James H.'Gibbons, 1735 E.Evanston Road, Tipp City, Ohio 45371 221 Filed: Aug. 27, 1971 211 Appl.No; 175,671

[52] US. Cl. 425/450, 100/271, 100/291, 425/DIG. 221 [51] Int. Cl. 829iH00 [58] Field of Search 425/450, 242, 453; 164/137, 341, 342, 343;100/271, 291

[56] References Cited UNITED STATES PATENTS 2,115,590 4/1938 Ryder425/450 X 2,370,622 3/1945 Gastlow 425/450 X 2,586,896 2/1952 Wittlin164/343 X 3,327,353 6/1967 Eggenberger... 425/450 3,543,346 12/1970Breher 425/242 3,669,593 6/1972 Cyriax 425/242 X FOREIGN PATENTS ORAPPLICATIONS 885,480 Germany 425/242 Primary Examiner-J. SpencerOverholser Assistant Examiner-Michael 0. Sutton Attorney-Jacox &Meckstroth 5 7 ABSTRACT A first mold member is supported by a platen formovement between open and closed positions relative to a mating secondmold member mounted on the frame which supports the platen. A firstwedge member extends across the back of the platen, and a second wedgemember is supported by the frame for aligned sliding engagement with thefirst wedge member to effect locking of the mold members after they areclosed. In one embodiment, the second wedge member is also supported forlateral movement to an offset position relative to the first wedgemember to provide for quickly opening and closing the mold members.Movement of the first mold member and the movement of the second wedgemember are produced by a set of fluid cylinders which are actuated intimed sequence and are effective to exert a continuous force to hold themold members in their closed positions. In another embodiment, thesecond wedge member is supported by a plate which may be quicklyretracted and extended for opening and closing the mold member.

9 Claims, 12 Drawing Figures PAFENIEBJM. 3 I978 MUIBFS A TTORNE Y5BJASASS PAINTED-M 3 ms WEE? 2 BF 5 l/VVE/VTOR JAMES H. GIBBONS A TTORNEY5 MOLD CAVITY LOCKING APPARATUS BACKGROUND OF THE INVENTION In the artof injection molding a plastics material, it is common to mount one moldmember on a stationary mold support platen and to mount the mating moldmember or another platen which is supported for reciprocating movementrelative to the stationary platen to provide for opening and closing ofthe mold members. Many forms of mold actuating devices have been used orproposed for opening and closing the mold members and for clamping andlocking the mold members together in their closed positions. Forexample, U.S. Pat. Nos. 2,319,479 and 2,586,896 show different forms ofmold locking devices which employ movable wedge members. U.S. Pat. No.3,195,186 discloses a molding machine which employs wedge type clampingmembers, and U.S. Pat. No. 3,262,158 shows a machine which uses fluidactuated toggle links for locking the mold members together.

To provide for positively locking a set of mold members in their closedposition, it has been found desirable to use wedge members which areplaced in compres sion during locking of the mold members by locatingthe wedge members directly in back of the movable mold member supportplaten. It has also been found desirable to provide for quickly openingand closing the mold members to minimize the molding cycle time, and touse a mechanism which is simple and economical in construction andcompensates for any wear of the mechanism. It is apparent aftercarefully reviewing the disclosures of the above patents, that the moldlocking mechanism shown in each of the patents, is lacking in providingone or more of these desirable features.

SUMMARY OF THE INVENTION The present invention is directed to moldingapparatus which incorporates an improved mechanism for quickly openingand closing a set of mold members and for positively locking the moldmembers together in their closed positions. The mechanism of theinvention is not only economical in construction, but also provides forcompensating for any thermal expansion and wear of the mechanism toassure that the mold members are positively secured in their closedpositions. As used herein, the term mold member is intended to includeany mold or die member which is used for producing a metalic ornon-metalic part or article.

In acordance with one embodiment of the invention, one member of a moldset, is mounted on a stationary head plate, and the mating mold memberis mounted on a support platen which is guided for movement relative tothe head plate. A pair of parallel spaced wedge plates are secured tothe movable support platen and are adapted to be engaged by acorresponding pair of mating wedge plates supported for longitudinalmovement by a carriage platen which is, in turn, supported for lateralmovement by a base plate. The reciprocating movement of the mold supportplaten, the longitudinal movement of the wedge plates, and the lateralmovement of the carriage platen, are produced by corresponding hydrauliccylinders.

After the mold members are closed, the relatively sliding wedge platesare effective to clamp or lock the mold members together with acontinuing positive force. To open the mold members, the wedge platesare released and shifted laterally to out-of-alignment positions so thatthe wedge plates move into interfitting relation when the movable moldmember is retracted or opened. Thus the locking device of the inventionprovides for quickly opening and closing the mold members so that thecycle time of the molding operation, is minimized. In another embodimentof the invention, a quick acting toggle mechanism is used to open andclose the mold members, and both sets of wedge plates are moved as aunit with the movable mold member.

Other features and advantages of the invention will be apparent from thefollowing description, the accompanying drawings and the appendedclaims.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an exploded perspective viewof molding apparatus constructed in accordance with the invention;

FIG. 2 is a plan view of the assembled mold support apparatus shown inFIG. 1, with a portion broken away and with the mold members shown inopen positions;

FIG. 3 is a plan view similar to FIG. 2 and showing the mold members inclosed positions; FIG. 4 is a section taken generally on the line 4--4of FIG. 2;

FIG. 5 is a section taken generally on the line 55 of FIG. 3. andillustrating the locking mechanism before it is actuated;

FIG. 6 is a fragmentary section similar to FIG. 5 and showing thelocking mechanism in its locked position;

FIG. 7 is a section taken generally on the line 7-7 of FIG. 4;

FIG. 8 is a section similar to FIG. 7 and taken generally on the line8-8 of FIG. 5;

FIG. 9 is a section similar to FIG. 7 and 8 and taken generally on theline 9-9 of FIG. 6;

FIG. 10 is a section similar to FIG. 4 and showing a modification of theapparatus of the invention;

FIG. 11 is an elevational view similar to FIG. 6 and showing anotherembodiment of the invention; and

FIG. 12 is a fragmentary section taken generally on the line 12-12 ofFIG. 11.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIGS. 1-3, theinvention is illustrated in the form of apparatus for supporting a setof mold members 20 and 22 which are adapted to receive a molded plasticmaterial from a suitable injection molding machine. It is to beunderstood, however, that the apparatus of the invention may also beused for supporting a mold or die set which is adapted to receive ametal or other material. The apparatus includes a frame 25 formed by ahead plate 26 rigidly connected to a base plate 28 by a set of four tiebolts or rods 29 which receive corresponding nuts 31. The head plate 26and base plate 28 are also rigidly connected by an upper support plate32 secured to the head and base plates by a set of cap screws 33. Themold member 22 is rigidly secured to the head plate 26 and is adapted toreceive molten plastic material through a passage schematically definedby a conduit 36.

The mold member 20 is rigidly secured to a mold support platen 38 whichis slidably mounted on the tie rods 29 to provide for movement of themold member 20 between an open position (FIG. 2) and a closed position(FIG. 3) relative to the mold member 22. The opening and the closing ofthe mold members 20 and 22 is produced by a double acting hydraulicfluid cylinder 40 which is mounted on the base plate 28. The cylinder 40has a piston rod 42 which extends parallel to the guide rods 29 and hasa forward end portion threaded into a hole 43 formed within the centerof the support platen 38.

A pair of upper and lower tracks 44 having an L- shaped cross section,are mounted on the base plate 28 in parallel spaced relation andslidably support a carriage plate 45 having flanges 46 which arereceived within the tracks 44. A laterally extending slot or keyway 48is formed within the front surface of the base plate 28 and receives apair of key members 49 which are also partly received within a slot 51formed within the back surface of the carriage plate 45. The key members49 and the keyways 48 and 51 cooperate with the tracks 44 to assure thatthe carriage plate 45 does not twist when it is shiftd horizontally andlaterally. A double acting hydraulic fluid cylinder 55 is mounted on aflange 56 secured to the base plate 28 and includes a piston rod 58having an end portion threaded into a tapped hole 59 formed within anear 61 secured to the carriage plate 45.

A wedge member 60 is supported by the carriage plate 45 for verticalmovement and includes a wedge support plate 62 which is connected to thecarriage plate 45 by a set of retaining plates 64 and a series of capscrews 66 which extend through corresponding holes within the carriageplate 45. The wedge support plate 62 is also connected to the carriageplate 45 by a pair of key members 69 which extend within a pair ofmating keyways 71 and 72 formed within the carriage plate 45 and thewedge support plate 62, respectively. The carriage plate 45 and thewedge support plate 62 also have corresponding clearance holes 73 and 74through which extends the piston rod 42 of the hydraulic cylinder 40.

The wedge member 60 also includes a pair of parallel spaced wedgeelements or plates 75 which are rigidly secured to the support plate 62and have corresponding sloping front surfaces 76. A pair of studs 78project upwardly from the wedge plates 75 and have enlarged headportions which are slidably received within an elongated guide track 79having a C-shaped crosssectional configuration. A double actinghydraulic fluid cylinder 80 is mounted on the upper tie plate 32 abovethe wedge member 60 and has a piston rod 82 with a lower end portionthreaded into a hole 83 formed within the center of the guide track 79.A guide pin 84 extends downwardly from the plate 32 and is receivedwithin a hole formed within the track 79. A pair of parallel spacedwedge elements or plates 85 are rigidly secured to the rear side of themold support platen 38 and have corresponding sloping rear surfaces 86which are adapted to mate with the sloping surfaces 76 of the wedgeplates 75.

Referring to FIGS. 2-9, the mold support and actuating apparatusoperates in the following manner. The molding of an article within themold members and 22 is commenced by actuating the hydraulic cylinder 40to extend the piston rod 42 so that the mold support platen 38 and theattached mold member 20 move to the closed position shown in FIG. 3. Thehydraulic cylinder 55 is then actuated to shift the wedge member 60laterally so that the wedge plates 75 are aligned with the wedge plates85 on the back of the mold support platen 38. The hydraulic cylinder 80is then actuated to extend the piston rod 82 and thereby press the wedgeplates downwardly against the wedge plates 85 to the locking positionshown in FIG. 9. The downward pressure on the wedge member 60 iscontinuously exerted during the molding operation while thethermoplastic material is injected into the cavity defined by the moldmembers 20 and 22.

After the article has been molded and the plastic material hassolidified by the circulation of cooling water within passages (notshown) within the mold members 20 and 22, the double acting hydrauliccylinder is again actuated to retract the wedge member 60 upwardly torelease the locking or clamping pressure exerted on the mold supportplaten 38 and return the wedge member 60 to the position shown in FIG.5. The hydraulic cylinder 55 is then actuated to extend thecorresponding piston rod 58 and thereby shift the wedge member 60laterally to a position (FIG. 2) where the wedge plates 75 are locatedin offset out-ofaligned relation to the wedge plates 85.

The hydraulic cylinder 40 is actuated to retract the platen 38 and themold member 20 to its open position (FIGS. 2 and 4) relative to the moldmember 22. The molded plastic part is able to drop downwardly be tweenthe bottom guide rods 29 into a suitable receiving container. When themold support platen 38 is retracted, the wedge plates are retracted intolaterally adjacent interfitting relation to the wedge plates 75 as shownin FIG. 2. The cycle is repeated to perform another molding operationand to produce another molded plastic part.

Referring to FIG. 10 which shows a modification of apparatus constructedin accordance with the invention, a head plate 96 and a base plate 98are not only rigidly connected by a series of tie rods 29 but are alsorigidly connected by a bed plate 99 and a series of screws 101. The moldmember 20 is supported by a platen having a base portion 106 which ismounted on the bed plate 99 by one V-shaped slide way (not shown) andone antifriction way 108. The wedge members 85 are secured to the backsurface of the platen 105 and are adapted to be engaged by the wedgeplates 75 of the wedge member 60 in the same manner as described abovein connection with the embodiment shown in FIGS. 1-9.

The platen 105 is moved on the bed plate 99 by a hydraulic fluidcylinder 110 which is mounted on a bracket 111 secured to the bed plate99. The cylinder 110 has a piston rod 112 secured to the base portion106 of the platen 105. This embodiment provides the feature that theweight of the platen 105 and the mold member 20 is not carried by thetie rods 29 and thereby eliminates any possible bending or downwarddeflection of the tie rods 29.

FIGS. 11 and 12 show another embodiment of the mold support andactuating apparatus of the invention. In this embodiment, the head plate116 is rigidly connected to a base plate 118 by a series of tie rods 119in the same manner as the embodiments shown in FIGS. 1-10. In thisembodiment, the mold member 20 is mounted on a platen 122 which, inturn, is mounted on the forward ends of a set of four guide rods 124.The rods 124 are received within preloaded antifriction cylindricalbearings 126 which are confined within corresponding bores formed in abase platen 128 slidably mounted on the tie rods 119.

A pair of wedge plates 130 are secured to the back surface of the platen122 and engage a corresponding pair of mating wedge plates 132 which aresupported for vertical movement by the base platen 128 in the samemanner as the wedge plate 75 is supported for vertical movement on thecarriage plate 45 in the embodiment of FIGS. 19. As shown in FIG. 11,the base platen 128 is connected to the base plate 118 by a togglemechanism 135 which includes a set of links 136 pivotally connected toeach other and to the base plate 118 and the base platen 128. A set oflinks 138 are also pivotally connected to each other and to the links136, and a fitting 139 connects the links 138 to the piston rod of ahydraulic fluid cylinder 140.

When the mold members 20 and 22 are in their closed positions (FIG. 11),the links 136 are aligned to form a rigid link between the platen 128and the base plate 118. The clamping and locking of the mold members isproduced by actuation of the hydraulic cylinder 80 which forces thewedge plates 132 downwardly against the wedge plates 130 to clamp orcompress the mold members 20 and 24 together. After the moldingoperation is completed, the mold members are opened by first retractingthe wedge plates 132 by actuating the cylinder 80. The quick opening ofthe mold members is then obtained by actuating'the hydraulic cylinder140 which quickly retracts the base platen 128 as a result of themechanical advantage provided by the toggle mechanism 135.

From the drawings and the above description, it is apparent that a moldsupporting and actuating apparatus constructed in accordance with theinvention, provides desirable features and advantages. For example, thewedge plates 75 and 85 or the plates 130 and 132 cooperate to clamp andlock mold members 20 and 22 together with a force which is distributedover a substantial area of the mold members. In addition, the hydrauliccylinder 80 is effective to exert a continuing locking force whichcompensates for elongation of the tie rods 29 as a result of thermalexpansion when the apparatus commences from a cold start up. Theconstant wedging force exerted by the wedge plates 75, is also effectiveto compensate for wear of the components after the apparatus has been inoperation for an extended period of time.

Another important feature is provided by the lateral shifting of thewedge plates 75 as produced by actuating the cylinder 55. That is, byshifting the wedge plates 75 laterally after the wedge plates have beenretracted upwardly, the mold support platen 38 may be quickly retractedto open the mold members, since the wedge plates 85 are free to extendinto laterally offset positions interfitting with the wedge plates 75.Thus it is not necessary to retract the wedge member 60 completely outof the path of the mold support platen 38, and as a result, theoperations of opening and closing the mold members may be quicklyperformed.

As mentioned above, the embodiment shown in FIG. provides the feature ofsupporting the weight of the platen 105 and the mold member with the bedplate 99 instead of with the tie rods 29. As a result, there is nobending of the tie rods 29, and the mold members 20 and 22 aremaintained in precise alignment. The embodiment shown in FIGS. 11 and 12provides for not only distributing the clamping or locking force over asubstantial area of the mold support platen 122, but also provides forrapid opening and closing of the mold members by quickly moving the baseplaten 128 through actuation of the toggle mechanism 135.

While the forms of apparatus herein described constitute preferredembodiments of the invention, it is to be understood that the inventionis not limited to these precise forms of apparatus, and that changes maybe made without departing from the scope and spirit of the invention.

What is claimed is:

1. Molding apparatus adapted to receive first and second mating moldmembers, comprising a frame having means for supporting the second moldmember, means mounted on said frame for supporting the first moldmembers for movement in a first direction between open and closedpositions relative to the second mold member, means for moving the firstmold member between said open and closed positions, first wedge meansconnected to said supporting means for the first mold member, secondwedge means positioned in alignment with said first wedge means, meansmounted on said frame and supporting said second wedge means formovement in a second direction generally normal to said first directionbetween a released position and a locked position engaging said firstwedge means to effect pressing of the first mold member against thesecond mold member, said supporting means for said second wedge meansalso providing for movement of said second wedge means in a thirddirection laterally to both said first and second directions to anoffset outof-alignment position relative to said first wedge means toprovide for quickly moving the first mold member to its open position,and means for moving said second wedge means between said locked andoffset positions through said released position.

2. Apparatus as defined in claim 1 wherein said first wedge meanscomprise a first set of spaced wedge ele ments, said second wedge meanscomprise a second set of spaced wedge elements, and said second set ofwedge elements are movable into interfitting relation with said firstset of wedge elements when the first mold member is moved to said openposition.

3. Molding apparatus adapted to receive first and second mating moldmembers, comprising a frame including a head member and a base member insubstantially parallel spaced relation, a plurality of parallel tiemembers rigidly connecting said head and base members, said head memberbeing adapted to receive the second mold member, a mold platenpositioned between said head and base members in substantially parallelspaced relation, a base platen positioned between said mold platen andsaid base member in substantially parallel spaced relation, a first setof spaced wedge elements secured to said mold platen, a carriage platesupported for movement by said base platen, a second set of spaced wedgeelements supported by said carriage plate and positioned in alignmentwith said first set of wedge elements, means for moving said carriageplaten laterally and generally parallel to said base platen to providefor movement of said second set of wedge elements between locked andreleased positions relative to said first set of wedge elements, togglelinkage means connecting said base member and said base platen, and

ing means for supporting the second mold member, means mounted on saidframe for supporting the first mold member for movement in a firstdirection between open and closed positions relative to the second moldmember, a first set of spaced wedge elements connected to saidsupporting means for the first mold member, a second set of spaced wedgeelements positioned in alignment with said first set of wedge elements,means connected to said frame and supporting said second set of wedgeelements for movement in a second direction generally normal to saidfirst direction between a released position and a locked positionengaging said first set of wedge elements to effect pressing of thefirst mold member against the second mold member, said latter supportingmeans also being effective to provide for movement of said second set ofwedge elements in a third direction laterally to both said first andsecond directions to positions in offset out-of-alignment relation withsaid first set of wedge elements, said sets of wedge elements beingmovable into interfitting relation when the first mold member is movedto said open position, and means for moving said supporting means forsaid second set of wedge elements.

5. Apparatus as defined in claim 4 wherein said first set of wedgeelements comprise a pair of parallel spaced wedge plates, said secondset of wedge elements comprise a corresponding pair of parallel spacedwedge plates, and said supporting means for said latter pair of wedgeplates is effective to provide for longitudinal movement of said wedgeplates between said released and locked positions and lateral movementof said wedge plates between said released and offset positions.

6. Apparatus as defined in claim 5 wherein said means supporting thefirst mold member comprise a platen, and said first and second sets ofwedge plates extend laterally across a substantial portion of saidplaten.

7. Apparatus as defined in claim 4 wherein said frame includes a headplate and a base plate in parallel spaced relation, a plurality ofparallel tie members rigidly connecting said head and base plates, saidhead plate being adapted to receive the second mold member, said meansfor supporting the first mold member including a platen positionedbetween said head and base plates in parallel spaced relation, saidsupporting means for said second set of wedge elements includes acarriage plate supported by said base plate for movement in onedirection, and said second set of wedge plates being supported by meansmounted on said carriage plate for movement in a direction generallyperpendicular to said one direction.

8. Apparatus as defined in claim 7 wherein said means for moving saidsecond set of wedge elements, include a first fluid cylinder connectedto move said carriage plate, and a second fluid cylinder connected tomove said means supporting said second set of wedge elements.

9. Apparatus as defined in claim 8 including a third fluid cylindermounted on said base plate and having a piston rod connected to saidplaten for moving the first mold member between said open and closedpositions, and saidcarriage plate defines an opening for receiving saidpiston rod.

* a: a: a:

1. Molding apparatus adapted to receive first and second mating moldmembers, comprising a frame having means for supporting the second moldmember, means mounted on said frame for supporting the first moldmembers for movement in a first direction between open and closedpositions relative to the second mold member, means for moving the firstmold member between said open and closed positions, first wedge meansconnected to said supporting means for the first mold member, secondwedge means positioned in alignment with said first wedge means, meansmounted on said frame and supporting said second wedge means formovement in a second direction generally normal to said first directionbetween a released position and a locked position engaging said firstwedge means to effect pressing of the first mold member against thesecond mold member, said supporting means for said second wedge meansalso providing for movement of said second wedge means in a thirddirection laterally to both said first and second directions to anoffset out-of-alignment position relative to said first wedge means toprovide for quickly moving the first mold member to its open posiTion,and means for moving said second wedge means between said locked andoffset positions through said released position.
 2. Apparatus as definedin claim 1 wherein said first wedge means comprise a first set of spacedwedge elements, said second wedge means comprise a second set of spacedwedge elements, and said second set of wedge elements are movable intointerfitting relation with said first set of wedge elements when thefirst mold member is moved to said open position.
 3. Molding apparatusadapted to receive first and second mating mold members, comprising aframe including a head member and a base member in substantiallyparallel spaced relation, a plurality of parallel tie members rigidlyconnecting said head and base members, said head member being adapted toreceive the second mold member, a mold platen positioned between saidhead and base members in substantially parallel spaced relation, a baseplaten positioned between said mold platen and said base member insubstantially parallel spaced relation, a first set of spaced wedgeelements secured to said mold platen, a carriage plate supported formovement by said base platen, a second set of spaced wedge elementssupported by said carriage plate and positioned in alignment with saidfirst set of wedge elements, means for moving said carriage platenlaterally and generally parallel to said base platen to provide formovement of said second set of wedge elements between locked andreleased positions relative to said first set of wedge elements, togglelinkage means connecting said base member and said base platen, andmeans for actuating said toggle linkage means to effect rapid movementof said base platen between an extended position and a retractedposition relative to said base member to provide for quickly opening andclosing the mold members.
 4. Molding apparatus adapted to receive firstand second mating mold members, comprising a frame having means forsupporting the second mold member, means mounted on said frame forsupporting the first mold member for movement in a first directionbetween open and closed positions relative to the second mold member, afirst set of spaced wedge elements connected to said supporting meansfor the first mold member, a second set of spaced wedge elementspositioned in alignment with said first set of wedge elements, meansconnected to said frame and supporting said second set of wedge elementsfor movement in a second direction generally normal to said firstdirection between a released position and a locked position engagingsaid first set of wedge elements to effect pressing of the first moldmember against the second mold member, said latter supporting means alsobeing effective to provide for movement of said second set of wedgeelements in a third direction laterally to both said first and seconddirections to positions in offset out-of-alignment relation with saidfirst set of wedge elements, said sets of wedge elements being movableinto interfitting relation when the first mold member is moved to saidopen position, and means for moving said supporting means for saidsecond set of wedge elements.
 5. Apparatus as defined in claim 4 whereinsaid first set of wedge elements comprise a pair of parallel spacedwedge plates, said second set of wedge elements comprise a correspondingpair of parallel spaced wedge plates, and said supporting means for saidlatter pair of wedge plates is effective to provide for longitudinalmovement of said wedge plates between said released and locked positionsand lateral movement of said wedge plates between said released andoffset positions.
 6. Apparatus as defined in claim 5 wherein said meanssupporting the first mold member comprise a platen, and said first andsecond sets of wedge plates extend laterally across a substantialportion of said platen.
 7. Apparatus as defined in claim 4 wherein saidframe includes a head plate and a base plate in parallel spacedrelation, a plurality of parallel tie members riGidly connecting saidhead and base plates, said head plate being adapted to receive thesecond mold member, said means for supporting the first mold memberincluding a platen positioned between said head and base plates inparallel spaced relation, said supporting means for said second set ofwedge elements includes a carriage plate supported by said base platefor movement in one direction, and said second set of wedge plates beingsupported by means mounted on said carriage plate for movement in adirection generally perpendicular to said one direction.
 8. Apparatus asdefined in claim 7 wherein said means for moving said second set ofwedge elements, include a first fluid cylinder connected to move saidcarriage plate, and a second fluid cylinder connected to move said meanssupporting said second set of wedge elements.
 9. Apparatus as defined inclaim 8 including a third fluid cylinder mounted on said base plate andhaving a piston rod connected to said platen for moving the first moldmember between said open and closed positions, and said carriage platedefines an opening for receiving said piston rod.